Portable tension indicator



July 22, 1930.

w. R. MARTIN 1,771,339

PORTABLE TENS ION INDICATOR Filed Feb. 2, 1928 INVENTOR: 53 Wolfe!- B, l'10r'fm 4,, YEMWVLK l {2:9 5: ATTORNEY.

Patented July 22, 1930 UNITED STATES PATENT. OFFICE WALTER R. MARTIN, LONG BEACH, CALIFORNIA, ASSIGNOR, BY MES NE ASSIGN- MENTS, TO MARTIN-DECKER CORPORATION, OF LONG BEACH, CALIFORNIA, A COB- roaarron PORTABLE TENSION INDICATOR Application filed February 2, 1928. Serial No. 251,415.

I refer to my present invention as a or-table tension indicator for the reason t at, al though it is similar in principle to the socalled weight indicator described and claimed in my U. S. Patent application filed November '1, 1926 (Serial No. 145,683), the

unit which I herein describe and claim is particularly designed for use upon so-called messenger cables, high lines, elevator cables, guy lines, etc.,in which not only precision and ruggedness but avoidance of excessive weight are important considerations.

, It is an object of this invention to provide a unit, of the general character referred to, in which, a main casting or body member being preferably provided with an integral or removable handle, easily operable means are provided for the attachment of the mentioned unit to a cable kept under tension; and, in preferred embodiments of my invention, a disc-like movable member being referably formed integral with a so-called finger disposed centrally thereof, and said disc being adapted to impart pressure to a slightly mov: able diaphragm, or its equivalent, a removable ring is employed not only tosecure said diaphragm but to limit the play of said disc.

It is a further object of my invention, preferably so providing a peripheral bead upon the mentioned main casting as both-to protect the edge of the mentioned diaphragm and to reinforce the entire unit, to strengthen said main casting also by means such as a transverse rib, or the like,'this rib preferably ex tending directly between rugged lateral extensions provided .with cable-engaging clamps; and, in preferred'embodiments-of this invention, said main casting may be pro- 'vided also with means, such as'threaded plunger, for purposes of zero correction, (to adapt my units to use .at various temperatures without the admission or withdrawal of liquid) and also with a valved opening or openings suitable for ilse either in the filling (or emptying or refilling) of the same or in connecting the same with a recorder,in case a f permanent record of weights or pressuresis desired. Other objects of my .invention, in which at the ends 6f the mentioned rib (said rib then lying in substantially the same plane with any cable or other flexible element to which one of my units is applied, and all parts .being designed to withstand strains such as may result from a weight or load up to 20,000 lbs. or more) may be best appreciated from the following description or an illustrative embodiment of this invention, taken in connection with the appended claims and the accompanying drawing, in which- F 1g. I is an elevational view, with parts broken away.

Fig. 2 is ,a longitudinal diametrical sec tional view.

Fig. 3'is a detail end view, taken substantially as indicated by the arrow 3 of Fig. 2.

Fig. 4 is a'detail view showing one optional construction suitable for use in one of the clamping organizations referred to. (Cf. lower portion of Fig. 3.)

Fig. 5 is a detail showing the boss for attaching the gauge. v

In that easily portable unit chosen for urposes of illustration, this form beingbllght enough to beeasily carried up a telegraph pole, or the like, for use in determining the tension upon a so-called messenger cable (or upon any guy rope or the like) a. main casting body member 40, (which may advantageously be cast from a light material such as aluminum alloy) is provided not only with rugged lateral extensions 41, 41, between which may extcnd a reinforcing rib 42, but with a peripheral bead 43. This bead may serve not only as a reinforcement, concealing and protectin the edge of an optional diaphragm 46 which may be formed rom a substantially inextensible but flexible gasket stock, or the like, including layers of rubber and layers of textile fabric) but to receive an undercut ring 4 7,the latter being shown as transversely bored for bolts 48, extending also through a thickened rim 49, integral with the main body 40. The ring 47, whether or not used to retain the mentioned diaphragm, may serve to efi'ect either a tight closure or to limit the play of an intertitting but relatively movable disc-like member 50,with which a finger 51 may be integral. The inner circular edge of the member is preferably rounded, to obviate undue wear upon any liquid-confining element such as the mentioned diaphragm; and the latter may be slightly convexed, or it may merely be given a sloppy fit, in a manner favorable to its yielding s ightly, under pressure of said disclike movable n1ember,to vary the capacity of any liquid-containing chamber C provided therein or within the main body 40.

The body 40 may be provided with an integral or removable but rigid handle 52, with a lower threaded boss 53 for the direct attachment of a gauge or recorder, 54, and with radially-extending and interiorly threaded bosses 55 and 56,all of said bosses being hollow and the latter being adapted respectively to receive a petcock 57 (shown as capped, and intended primarily for use in filling, but capable of connection to a recorder or other control element) and to receive a pressure-adjusting or zero-correcting screw 58. The screw 58 is shown as provided with a gland organization 59,which may include one or more special washers between whose oppositely-inclined or bevelled surfaces a suitable packing may be so interposed as to be inwardly wedged by any movement of approach between said special washers.

All of the mentioned parts being disposed with due regard to balance and symmetry, cable-seat members in the form of osses 60, 60', projecting to a standardized distance but not to the same distance as the central finger 51 (and any of these being optionally provided with an insert 61 of steel, or the like, to reduce wear) are shown as integral with the lateral extensions 41, 41; and, to complete a cable-deflecting organization, each of said. extensions may be bored, at two points symmetrically disposed with reference to a cable-seat boss, to receive and to guide a pair of transversely slidable bolts 62, 62' carrying so-called strong-backs 63, 64,to which movement may be imparted in any suitable wav.

Each cable-engaging or inner strong-back 63 is shown as so slotted at 65 as to permit a pivotal movement upon the adjacent bolt, to facilitate a plication of a unit even to a cable kept un er tension; and each may also be provided with a cable-receiving notch 66. Each outer strong-back 64 is shown as centrall provided with a threaded opening 67 for t 1e reception of a threaded manipulating bolt; and each of these bolts 68, 68' may be provided not only with a grip controlling crank 69 at its outer end, but with a ball 70 at its inner end,--the latter being preferably locked in place by a suitable keeper 71, so that the said ball can serve both as a bearing element and to render the described grip-controlling organizations ositive during movement of the strong-bac s (shown as retained in spaced relationship by suitable shoulders upon the transversely slidable bolts 62, 62) in either direction.

It will be seen that the threaded bolts 68, 68 and the cranks integral therewith project sufficiently to afford incidental protection to any gauge or other pressure-responsive instrument disposed therebetween; that this type of unit requires the use of different calibration curves for different sizes and kinds of cables; and that, if changes in tension are to be automatically, continuously, or continuously and automatically revealed, not more than one of the bolts 68 should be so tightened (or not more than one of the clamping couples should be so designed) as absolutely to prevent slippage of cable therethrough.

In order to enable variations in the tension of a cable 72 to be immediately reflected,

without intervening readjustments of either of the bolts 68, 68', in any pressure-responsive instrument 54, at least one of the described cable-deflecting clamp organizations may, if desired, be provided with a suitable friction-reducin means. For the purpose last referred tofi suggest the introduction of one or more small pulleys 73, 7 4, preferably having annularly concave or double-cone surfaces, into one of the cable-seat bosses and into an oppositely-positioned and Juitably notched strong-back,-somewhat as indicated at 60 and 66, Fig. 4; but it will be understood not only that any preferred friction-reducing means may be employed (with or without roller bearings, or the like, not shown) but that such means may ordinarily be entirely dispensed with, if desired. In

either case, the clamping bolts 68, 68' may be simply screwed up about as far as they will go, with a given cable therebetween, and the pressure indicated by the instrument 54 will then correspond with some specific pull, such as may be expressed in pounds or tons,sustained b the cable 72, or its equivalent. The use of 'riction-reducing means, such as one or more of the small pulleys 73, 7 4, can thus serve to obviate all occasion for repeatedly releasing and again tightening one of the,

clamping bolts 68, 68, in order to obtain continuous or new readings of the instrument 54, if and as conditions chan e.

Although I have herein described a single complete embodiment of m invention, suggesting certain optional details it will be understood not only that various features of this invention may be independently used but also that numerous additional modifications thereof might easily be devised, by workers in the arts to which this case relates, without involving the slightest departure from the spirit and scope of said invention,' as the same is indicated above and in the following claims.

I claim 1. Hydraulic apparatus for revealing loads which comprises: a flat shallow main body member provided with a flattened fluid holding cavity; an interfitting flat member capable of limited rcciprocatory movement relatively thereto; means for confining a fluid in the said fluid holding cavity between said body member and said interfitting member; means for so securing a flexible element relatively thereto as to produce a predetermined deflection in said flexible element; and means, secul'ed to and carried upon said body portion, for revealing the pressure upon said fluid, caused by any load on said flexible element.

2. Hydraulic apparatus for revealing loads which comprises: a main body member; an interfitting member capable of limited reciprocatory movement relatively thereto; means for confining a fluid in a space therebetween; and means for so securing a flexible element relatively thereto as to produce a predetermined deflection in said flexible elemcnt,said body element being provided with lateral extensions carrying clamps, and with a reinforcing rib, extending between said lateral extensions.

3. Hydraulic apparatus for revealing loads which comprises: a body member; an interfitting member capable of limited reciprocatory movement relatively thereto; and means including a finger for so securing a flexible element relatively thereto as to' roduce a predetermined deflection in said ex ible element,said movable member being in the form-of a disc with which the mentioned finger is integral.

4. Hydraulic apparatus for revealing loads which comprises: a body member; an interfitting member capable of llmited reciprocatory movement relatively thereto; and means for so securing a flexible element relatively thereto as toproduce a predetermined deflection in said flexible element, said maln body being provided with extensions carrying clamps which comprise pivoted strongbacks and threaded means for the same.

5. Hydraulic apparatus for revealing loads which comprises: a body member; an interfitting member capable of limited reciprocatory movement relatively thereto; means for so securing a flexible element relatively thereto as to produce a predetermined deflection in said flexible element,said main body being provided with extensions carrying clamps for manipulating the same, and

manipulating P one of said clamps being provided with friction-redu'cing means.

6. Hydraulic apparatus for revealing loads which comprises: a body member; an interfitting member capable of limited reciprocatory movement relatively thereto; means for confinin a fluid in a space therebetween; and means or so securing a flexible element relatively thereto as to produce a predetermined deflection in said flexible element,a diaphragm, comprised in said confining means, being interposed between said movable member and said mainbody and retained by means comprising an undercut ring. I

7. Hydraulic apparatus for revealing loads which comprises: a body member; an interfitting member capable of limited reciprocatory movement relatively thereto; means for confining a 'fluid in a space therebetween; and means for so securing a flexible element relatively thereto as to produce a predetermined deflection in said flexible element,-a dia- )hragm, comprised in said confining means,

eing inter osed between said movable mem-' her and sai main body and retained by means comprising an undercut rin which serves also to limit play of said movabl e member.

8. An organization of the general character defined in claim 1, in which said means for producing predetermined deflections comrises a substantially central pressure-receiving finger, which is integral with said relatively movable part.

9. An organization of the general character defined in claim 1, in which said means for producing predetermined deflections comprises a substantially central pressure-receiving finger, integral with said relatively movab e member, and a air of oppositel disposed cable-seat mem ers, integral wit said main body.

10. An organization of the general character defined/in claim 1, in which said means for producing predetermined deflections comrises a substantially central pressure-receiving finger which isintegral withsaid relativel movable part and in which rope engaging osses are. provided, having reinforcing inserts.

11. An organization of the general character defined in claim 1, in which said means for producing predetermined deflection comrises a substantially central pressure-receivmg finger, integral with said relatively movable part, and in which cable-enga ing bosses are provided, each of said bosses Eein associated with means for drawing a flexi le element thereto. 7

12. For use in an organization of the general character defined in claim 1: zero-correcting means comprising a screw plunger and packing means therefor.

13. An or anization of the general character defined in claim 1 in which said main body member is provided with a valved filling opening.

14. An organization of the general character defined in claim 1 in which said main body member is provided with a means for the removable attachment of a handle thereto.

15. An organization of the general character found in claim 1 in which said main body member is rovided with a means for the attachment o a handle thereto and with a zerocorrecting means and a filling opening which are radially and substantially symmetrically disposed with reference thereto.

In witness whereof, I have hereunto aflixed my signature.

WALTER R. MARTIN. 

